/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved. This software is open source. See
 * the bottom of this file for the licence.
 */

package org.dom4j.io;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

import org.dom4j.Attribute;
import org.dom4j.CDATA;
import org.dom4j.Comment;
import org.dom4j.Document;
import org.dom4j.DocumentType;
import org.dom4j.Element;
import org.dom4j.Entity;
import org.dom4j.Namespace;
import org.dom4j.Node;
import org.dom4j.ProcessingInstruction;
import org.dom4j.Text;
import org.dom4j.tree.NamespaceStack;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;
import org.xml.sax.XMLReader;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.helpers.XMLFilterImpl;

/**
 * <p>
 * <code>XMLWriter</code> takes a DOM4J tree and formats it to a stream as XML. It can also take SAX
 * events too so can be used by SAX clients as this object implements the
 * {@link org.xml.sax.ContentHandler}and {@link LexicalHandler} interfaces. as well. This formatter
 * performs typical document formatting. The XML declaration and processing instructions are always
 * on their own lines. An {@link OutputFormat}object can be used to define how whitespace is handled
 * when printing and allows various configuration options, such as to allow suppression of the XML
 * declaration, the encoding declaration or whether empty documents are collapsed.
 * </p>
 * <p>
 * There are <code>write(...)</code> methods to print any of the standard DOM4J classes, including
 * <code>Document</code> and <code>Element</code>, to either a <code>Writer</code> or an
 * <code>OutputStream</code>. Warning: using your own <code>Writer</code> may cause the writer's
 * preferred character encoding to be ignored. If you use encodings other than UTF8, we recommend
 * using the method that takes an OutputStream instead.
 * </p>
 * 
 * @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
 * @author Joseph Bowbeer
 * @version $Revision: 1.2 $
 */
public class XMLWriter extends XMLFilterImpl implements LexicalHandler
{
    private static final String PAD_TEXT = " ";

    protected static final String[] LEXICAL_HANDLER_NAMES = {
            "http://xml.org/sax/properties/lexical-handler",
            "http://xml.org/sax/handlers/LexicalHandler" };

    protected static final OutputFormat DEFAULT_FORMAT = new OutputFormat();

    /** Should entityRefs by resolved when writing ? */
    private boolean resolveEntityRefs = true;

    /**
     * Stores the last type of node written so algorithms can refer to the previous node type
     */
    protected int lastOutputNodeType;

    /**
     * Stores if the last written element node was a closing tag or an opening tag.
     */
    private boolean lastElementClosed = false;

    /** Stores the xml:space attribute value of preserve for whitespace flag */
    protected boolean preserve = false;

    /** The Writer used to output to */
    protected Writer writer;

    /** The Stack of namespaceStack written so far */
    private NamespaceStack namespaceStack = new NamespaceStack();

    /** The format used by this writer */
    private OutputFormat format;

    /** whether we should escape text */
    private boolean escapeText = true;

    /**
     * The initial number of indentations (so you can print a whole document indented, if you like)
     */
    private int indentLevel = 0;

    /** buffer used when escaping strings */
    private StringBuffer buffer = new StringBuffer();

    /**
     * whether we have added characters before from the same chunk of characters
     */
    private boolean charsAdded = false;

    private char lastChar;

    /** Whether a flush should occur after writing a document */
    private boolean autoFlush;

    /** Lexical handler we should delegate to */
    private LexicalHandler lexicalHandler;

    /**
     * Whether comments should appear inside DTD declarations - defaults to false
     */
    private boolean showCommentsInDTDs;

    /** Is the writer curerntly inside a DTD definition? */
    private boolean inDTD;

    /** The namespaces used for the current element when consuming SAX events */
    private Map namespacesMap;

    /**
     * what is the maximum allowed character code such as 127 in US-ASCII (7 bit) or 255 in ISO- (8
     * bit) or -1 to not escape any characters (other than the special XML characters like &lt; &gt;
     * &amp;)
     */
    private int maximumAllowedCharacter;

    public XMLWriter(Writer writer)
    {
        this(writer, DEFAULT_FORMAT);
    }

    public XMLWriter(Writer writer, OutputFormat format)
    {
        this.writer = writer;
        this.format = format;
        namespaceStack.push(Namespace.NO_NAMESPACE);
    }

    public XMLWriter()
    {
        this.format = DEFAULT_FORMAT;
        this.writer = new BufferedWriter(new OutputStreamWriter(System.out));
        this.autoFlush = true;
        namespaceStack.push(Namespace.NO_NAMESPACE);
    }

    public XMLWriter(OutputStream out) throws UnsupportedEncodingException
    {
        this.format = DEFAULT_FORMAT;
        this.writer = createWriter(out, format.getEncoding());
        this.autoFlush = true;
        namespaceStack.push(Namespace.NO_NAMESPACE);
    }

    public XMLWriter(OutputStream out, OutputFormat format) throws UnsupportedEncodingException
    {
        this.format = format;
        this.writer = createWriter(out, format.getEncoding());
        this.autoFlush = true;
        namespaceStack.push(Namespace.NO_NAMESPACE);
    }

    public XMLWriter(OutputFormat format) throws UnsupportedEncodingException
    {
        this.format = format;
        this.writer = createWriter(System.out, format.getEncoding());
        this.autoFlush = true;
        namespaceStack.push(Namespace.NO_NAMESPACE);
    }

    public void setWriter(Writer writer)
    {
        this.writer = writer;
        this.autoFlush = false;
    }

    public void setOutputStream(OutputStream out) throws UnsupportedEncodingException
    {
        this.writer = createWriter(out, format.getEncoding());
        this.autoFlush = true;
    }

    /**
     * DOCUMENT ME!
     * 
     * @return true if text thats output should be escaped. This is enabled by default. It could be
     *         disabled if the output format is textual, like in XSLT where we can have xml, html or
     *         text output.
     */
    public boolean isEscapeText()
    {
        return escapeText;
    }

    /**
     * Sets whether text output should be escaped or not. This is enabled by default. It could be
     * disabled if the output format is textual, like in XSLT where we can have xml, html or text
     * output.
     * 
     * @param escapeText
     *            DOCUMENT ME!
     */
    public void setEscapeText(boolean escapeText)
    {
        this.escapeText = escapeText;
    }

    /**
     * Set the initial indentation level. This can be used to output a document (or, more likely, an
     * element) starting at a given indent level, so it's not always flush against the left margin.
     * Default: 0
     * 
     * @param indentLevel
     *            the number of indents to start with
     */
    public void setIndentLevel(int indentLevel)
    {
        this.indentLevel = indentLevel;
    }

    /**
     * Returns the maximum allowed character code that should be allowed unescaped which defaults to
     * 127 in US-ASCII (7 bit) or 255 in ISO- (8 bit).
     * 
     * @return DOCUMENT ME!
     */
    public int getMaximumAllowedCharacter()
    {
        if (maximumAllowedCharacter == 0)
        {
            maximumAllowedCharacter = defaultMaximumAllowedCharacter();
        }

        return maximumAllowedCharacter;
    }

    /**
     * Sets the maximum allowed character code that should be allowed unescaped such as 127 in
     * US-ASCII (7 bit) or 255 in ISO- (8 bit) or -1 to not escape any characters (other than the
     * special XML characters like &lt; &gt; &amp;) If this is not explicitly set then it is
     * defaulted from the encoding.
     * 
     * @param maximumAllowedCharacter
     *            The maximumAllowedCharacter to set
     */
    public void setMaximumAllowedCharacter(int maximumAllowedCharacter)
    {
        this.maximumAllowedCharacter = maximumAllowedCharacter;
    }

    /**
     * Flushes the underlying Writer
     * 
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void flush() throws IOException
    {
        writer.flush();
    }

    /**
     * Closes the underlying Writer
     * 
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void close() throws IOException
    {
        writer.close();
    }

    /**
     * Writes the new line text to the underlying Writer
     * 
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void println() throws IOException
    {
        writer.write(format.getLineSeparator());
    }

    /**
     * Writes the given {@link Attribute}.
     * 
     * @param attribute
     *            <code>Attribute</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Attribute attribute) throws IOException
    {
        writeAttribute(attribute);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * <p>
     * This will print the <code>Document</code> to the current Writer.
     * </p>
     * <p>
     * Warning: using your own Writer may cause the writer's preferred character encoding to be
     * ignored. If you use encodings other than UTF8, we recommend using the method that takes an
     * OutputStream instead.
     * </p>
     * <p>
     * Note: as with all Writers, you may need to flush() yours after this method returns.
     * </p>
     * 
     * @param doc
     *            <code>Document</code> to format.
     * @throws IOException
     *             if there's any problem writing.
     */
    public void write(Document doc) throws IOException
    {
        writeDeclaration();

        if (doc.getDocType() != null)
        {
            indent();
            writeDocType(doc.getDocType());
        }

        for (int i = 0, size = doc.nodeCount(); i < size; i++)
        {
            Node node = doc.node(i);
            writeNode(node);
        }

        writePrintln();

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * <p>
     * Writes the <code>{@link Element}</code>, including its <code>{@link
     * Attribute}</code> s, and its value, and all its content (child nodes) to the current Writer.
     * </p>
     * 
     * @param element
     *            <code>Element</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Element element) throws IOException
    {
        writeElement(element);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link CDATA}.
     * 
     * @param cdata
     *            <code>CDATA</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(CDATA cdata) throws IOException
    {
        writeCDATA(cdata.getText());

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link Comment}.
     * 
     * @param comment
     *            <code>Comment</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Comment comment) throws IOException
    {
        writeComment(comment.getText());

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link DocumentType}.
     * 
     * @param docType
     *            <code>DocumentType</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(DocumentType docType) throws IOException
    {
        writeDocType(docType);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link Entity}.
     * 
     * @param entity
     *            <code>Entity</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Entity entity) throws IOException
    {
        writeEntity(entity);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link Namespace}.
     * 
     * @param namespace
     *            <code>Namespace</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Namespace namespace) throws IOException
    {
        writeNamespace(namespace);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link ProcessingInstruction}.
     * 
     * @param processingInstruction
     *            <code>ProcessingInstruction</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(ProcessingInstruction processingInstruction) throws IOException
    {
        writeProcessingInstruction(processingInstruction);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * <p>
     * Print out a {@link String}, Perfoms the necessary entity escaping and whitespace stripping.
     * </p>
     * 
     * @param text
     *            is the text to output
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(String text) throws IOException
    {
        writeString(text);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link Text}.
     * 
     * @param text
     *            <code>Text</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Text text) throws IOException
    {
        writeString(text.getText());

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given {@link Node}.
     * 
     * @param node
     *            <code>Node</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Node node) throws IOException
    {
        writeNode(node);

        if (autoFlush)
        {
            flush();
        }
    }

    /**
     * Writes the given object which should be a String, a Node or a List of Nodes.
     * 
     * @param object
     *            is the object to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void write(Object object) throws IOException
    {
        if (object instanceof Node)
        {
            write((Node) object);
        }
        else if (object instanceof String)
        {
            write((String) object);
        }
        else if (object instanceof List)
        {
            List list = (List) object;

            for (int i = 0, size = list.size(); i < size; i++)
            {
                write(list.get(i));
            }
        }
        else if (object != null)
        {
            throw new IOException("Invalid object: " + object);
        }
    }

    /**
     * <p>
     * Writes the opening tag of an {@link Element}, including its {@link Attribute}s but without
     * its content.
     * </p>
     * 
     * @param element
     *            <code>Element</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void writeOpen(Element element) throws IOException
    {
        writer.write("<");
        writer.write(element.getQualifiedName());
        writeAttributes(element);
        writer.write(">");
    }

    /**
     * <p>
     * Writes the closing tag of an {@link Element}
     * </p>
     * 
     * @param element
     *            <code>Element</code> to output.
     * @throws IOException
     *             DOCUMENT ME!
     */
    public void writeClose(Element element) throws IOException
    {
        writeClose(element.getQualifiedName());
    }

    // XMLFilterImpl methods
    // -------------------------------------------------------------------------
    @Override
	public void parse(InputSource source) throws IOException, SAXException
    {
        installLexicalHandler();
        super.parse(source);
    }

    @Override
	public void setProperty(String name, Object value) throws SAXNotRecognizedException,
            SAXNotSupportedException
    {
        for (int i = 0; i < LEXICAL_HANDLER_NAMES.length; i++)
        {
            if (LEXICAL_HANDLER_NAMES[i].equals(name))
            {
                setLexicalHandler((LexicalHandler) value);

                return;
            }
        }

        super.setProperty(name, value);
    }

    @Override
	public Object getProperty(String name) throws SAXNotRecognizedException,
            SAXNotSupportedException
    {
        for (int i = 0; i < LEXICAL_HANDLER_NAMES.length; i++)
        {
            if (LEXICAL_HANDLER_NAMES[i].equals(name))
            {
                return getLexicalHandler();
            }
        }

        return super.getProperty(name);
    }

    public void setLexicalHandler(LexicalHandler handler)
    {
        if (handler == null)
        {
            throw new NullPointerException("Null lexical handler");
        }
        else
        {
            this.lexicalHandler = handler;
        }
    }

    public LexicalHandler getLexicalHandler()
    {
        return lexicalHandler;
    }

    // ContentHandler interface
    // -------------------------------------------------------------------------
    @Override
	public void setDocumentLocator(Locator locator)
    {
        super.setDocumentLocator(locator);
    }

    @Override
	public void startDocument() throws SAXException
    {
        try
        {
            writeDeclaration();
            super.startDocument();
        }
        catch (IOException e)
        {
            handleException(e);
        }
    }

    @Override
	public void endDocument() throws SAXException
    {
        super.endDocument();

        if (autoFlush)
        {
            try
            {
                flush();
            }
            catch (IOException e)
            {}
        }
    }

    @Override
	public void startPrefixMapping(String prefix, String uri) throws SAXException
    {
        if (namespacesMap == null)
        {
            namespacesMap = new HashMap();
        }

        namespacesMap.put(prefix, uri);
        super.startPrefixMapping(prefix, uri);
    }

    @Override
	public void endPrefixMapping(String prefix) throws SAXException
    {
        super.endPrefixMapping(prefix);
    }

    @Override
	public void startElement(String namespaceURI, String localName, String qName,
            Attributes attributes) throws SAXException
    {
        try
        {
            charsAdded = false;

            writePrintln();
            indent();
            writer.write("<");
            writer.write(qName);
            writeNamespaces();
            writeAttributes(attributes);
            writer.write(">");
            ++indentLevel;
            lastOutputNodeType = Node.ELEMENT_NODE;
            lastElementClosed = false;

            super.startElement(namespaceURI, localName, qName, attributes);
        }
        catch (IOException e)
        {
            handleException(e);
        }
    }

    @Override
	public void endElement(String namespaceURI, String localName, String qName) throws SAXException
    {
        try
        {
            charsAdded = false;
            --indentLevel;

            if (lastElementClosed)
            {
                writePrintln();
                indent();
            }

            // XXXX: need to determine this using a stack and checking for
            // content / children
            boolean hadContent = true;

            if (hadContent)
            {
                writeClose(qName);
            }
            else
            {
                writeEmptyElementClose(qName);
            }

            lastOutputNodeType = Node.ELEMENT_NODE;
            lastElementClosed = true;

            super.endElement(namespaceURI, localName, qName);
        }
        catch (IOException e)
        {
            handleException(e);
        }
    }

    @Override
	public void characters(char[] ch, int start, int length) throws SAXException
    {
        if ((ch == null) || (ch.length == 0) || (length <= 0))
        {
            return;
        }

        try
        {
            /*
             * we can't use the writeString method here because it's possible we don't receive all
             * characters at once and calling writeString would cause unwanted spaces to be added in
             * between these chunks of character arrays.
             */
            String string = String.valueOf(ch, start, length);

            if (escapeText)
            {
                string = escapeElementEntities(string);
            }

            if (format.isTrimText())
            {
                if ((lastOutputNodeType == Node.TEXT_NODE) && !charsAdded)
                {
                    writer.write(' ');
                }
                else if (charsAdded && Character.isWhitespace(lastChar))
                {
                    writer.write(' ');
                }
                else if (lastOutputNodeType == Node.ELEMENT_NODE && format.isPadText()
                        && lastElementClosed && Character.isWhitespace(ch[0]))
                {
                    writer.write(PAD_TEXT);
                }

                String delim = "";
                StringTokenizer tokens = new StringTokenizer(string);

                while (tokens.hasMoreTokens())
                {
                    writer.write(delim);
                    writer.write(tokens.nextToken());
                    delim = " ";
                }
            }
            else
            {
                writer.write(string);
            }

            charsAdded = true;
            lastChar = ch[(start + length) - 1];
            lastOutputNodeType = Node.TEXT_NODE;

            super.characters(ch, start, length);
        }
        catch (IOException e)
        {
            handleException(e);
        }
    }

    @Override
	public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException
    {
        super.ignorableWhitespace(ch, start, length);
    }

    @Override
	public void processingInstruction(String target, String data) throws SAXException
    {
        try
        {
            indent();
            writer.write("<?");
            writer.write(target);
            writer.write(" ");
            writer.write(data);
            writer.write("?>");
            writePrintln();
            lastOutputNodeType = Node.PROCESSING_INSTRUCTION_NODE;

            super.processingInstruction(target, data);
        }
        catch (IOException e)
        {
            handleException(e);
        }
    }

    // DTDHandler interface
    // -------------------------------------------------------------------------
    @Override
	public void notationDecl(String name, String publicID, String systemID) throws SAXException
    {
        super.notationDecl(name, publicID, systemID);
    }

    @Override
	public void unparsedEntityDecl(String name, String publicID, String systemID,
            String notationName) throws SAXException
    {
        super.unparsedEntityDecl(name, publicID, systemID, notationName);
    }

    // LexicalHandler interface
    // -------------------------------------------------------------------------
    @Override
	public void startDTD(String name, String publicID, String systemID) throws SAXException
    {
        inDTD = true;

        try
        {
            writeDocType(name, publicID, systemID);
        }
        catch (IOException e)
        {
            handleException(e);
        }

        if (lexicalHandler != null)
        {
            lexicalHandler.startDTD(name, publicID, systemID);
        }
    }

    @Override
	public void endDTD() throws SAXException
    {
        inDTD = false;

        if (lexicalHandler != null)
        {
            lexicalHandler.endDTD();
        }
    }

    @Override
	public void startCDATA() throws SAXException
    {
        try
        {
            writer.write("<![CDATA[");
        }
        catch (IOException e)
        {
            handleException(e);
        }

        if (lexicalHandler != null)
        {
            lexicalHandler.startCDATA();
        }
    }

    @Override
	public void endCDATA() throws SAXException
    {
        try
        {
            writer.write("]]>");
        }
        catch (IOException e)
        {
            handleException(e);
        }

        if (lexicalHandler != null)
        {
            lexicalHandler.endCDATA();
        }
    }

    @Override
	public void startEntity(String name) throws SAXException
    {
        try
        {
            writeEntityRef(name);
        }
        catch (IOException e)
        {
            handleException(e);
        }

        if (lexicalHandler != null)
        {
            lexicalHandler.startEntity(name);
        }
    }

    @Override
	public void endEntity(String name) throws SAXException
    {
        if (lexicalHandler != null)
        {
            lexicalHandler.endEntity(name);
        }
    }

    @Override
	public void comment(char[] ch, int start, int length) throws SAXException
    {
        if (showCommentsInDTDs || !inDTD)
        {
            try
            {
                charsAdded = false;
                writeComment(new String(ch, start, length));
            }
            catch (IOException e)
            {
                handleException(e);
            }
        }

        if (lexicalHandler != null)
        {
            lexicalHandler.comment(ch, start, length);
        }
    }

    // Implementation methods
    // -------------------------------------------------------------------------
    protected void writeElement(Element element) throws IOException
    {
        int size = element.nodeCount();
        String qualifiedName = element.getQualifiedName();

        writePrintln();
        indent();

        writer.write("<");
        writer.write(qualifiedName);

        int previouslyDeclaredNamespaces = namespaceStack.size();
        Namespace ns = element.getNamespace();

        if (isNamespaceDeclaration(ns))
        {
            namespaceStack.push(ns);
            writeNamespace(ns);
        }

        // Print out additional namespace declarations
        boolean textOnly = true;

        for (int i = 0; i < size; i++)
        {
            Node node = element.node(i);

            if (node instanceof Namespace)
            {
                Namespace additional = (Namespace) node;

                if (isNamespaceDeclaration(additional))
                {
                    namespaceStack.push(additional);
                    writeNamespace(additional);
                }
            }
            else if (node instanceof Element)
            {
                textOnly = false;
            }
            else if (node instanceof Comment)
            {
                textOnly = false;
            }
        }

        writeAttributes(element);

        lastOutputNodeType = Node.ELEMENT_NODE;

        if (size <= 0)
        {
            writeEmptyElementClose(qualifiedName);
        }
        else
        {
            writer.write(">");

            if (textOnly)
            {
                // we have at least one text node so lets assume
                // that its non-empty
                writeElementContent(element);
            }
            else
            {
                // we know it's not null or empty from above
                ++indentLevel;

                writeElementContent(element);

                --indentLevel;

                writePrintln();
                indent();
            }

            writer.write("</");
            writer.write(qualifiedName);
            writer.write(">");
        }

        // remove declared namespaceStack from stack
        while (namespaceStack.size() > previouslyDeclaredNamespaces)
        {
            namespaceStack.pop();
        }

        lastOutputNodeType = Node.ELEMENT_NODE;
    }

    /**
     * Determines if element is a special case of XML elements where it contains an xml:space
     * attribute of "preserve". If it does, then retain whitespace.
     * 
     * @param element
     *            DOCUMENT ME!
     * @return DOCUMENT ME!
     */
    protected final boolean isElementSpacePreserved(Element element)
    {
        final Attribute attr = element.attribute("space");
        boolean preserveFound = preserve; // default to global state

        if (attr != null)
        {
            if ("xml".equals(attr.getNamespacePrefix()) && "preserve".equals(attr.getText()))
            {
                preserveFound = true;
            }
            else
            {
                preserveFound = false;
            }
        }

        return preserveFound;
    }
    
    protected void writeElementContentTrimWriteBuff(StringBuffer buff, String txt) throws IOException
    {
        if (buff != null)
            writeString(buff.toString());
        else
            writeString(txt);
    }
    
    protected void writeElementContentTrimPad(boolean textOnly, StringBuffer buff, Node lastText) throws IOException
    {
        if (!textOnly && format.isPadText() && 
                ((buff != null && Character.isWhitespace(buff.charAt(0))) || 
                        (lastText != null && Character.isWhitespace(lastText.getText().charAt(0)))))
            writer.write(PAD_TEXT);
    }
    
    protected void writeElementContentTrim(Element elm) throws IOException
    {
        Node lastText = null;
        StringBuffer buff = null;
        boolean textOnly = true;
        
        for(Object o : elm.content())
        {
            Node n = (Node) o;
            if (n instanceof Text)
            {
                if (lastText != null && buff == null)
                    buff = new StringBuffer(lastText.getText());
                
                if (lastText != null)
                    buff.append(n.getText());
                else 
                    lastText = n;
                
                continue;
            }
            
            writeElementContentTrimPad(textOnly, buff, lastText);
            
            if (lastText != null)
            {
                String txt = lastText.getText();
                writeElementContentTrimWriteBuff(buff, txt);
                if (format.isPadText() && 
                        Character.isWhitespace(txt.charAt(txt.length() - 1)))
                    writer.write(PAD_TEXT);
                
                buff = null;
            }
            
            lastText = null;
            textOnly = false;
            writeNode(n);
        }

        if (lastText != null)
        {
            writeElementContentTrimPad(textOnly, buff, lastText);
            writeElementContentTrimWriteBuff(buff, lastText.getText());
        }
    }
    
    /**
     * Outputs the content of the given element. If whitespace trimming is enabled then all adjacent
     * text nodes are appended together before the whitespace trimming occurs to avoid problems with
     * multiple text nodes being created due to text content that spans parser buffers in a SAX
     * parser.
     * 
     * @param element
     *            DOCUMENT ME!
     * @throws IOException
     *             DOCUMENT ME!
     */
    protected void writeElementContent(Element elm) throws IOException
    {
        boolean oldPreserve = preserve;

        if (format.isTrimText())
            preserve = isElementSpacePreserved(elm);

        if (format.isTrimText() && !preserve)
            writeElementContentTrim(elm);
        else
            for(Object o : elm.content())
            {
                Node n = (Node) o;
                if (!(n instanceof Text) && format.isPadText() &&
                        Character.isWhitespace(n.getText().charAt(n.getText().length() - 1)))
                    writer.write(PAD_TEXT);
                writeNode(n);
            }
        
        preserve = oldPreserve;
    }

    protected void writeCDATA(String text) throws IOException
    {
        writer.write("<![CDATA[");

        if (text != null)
        {
            writer.write(text);
        }

        writer.write("]]>");

        lastOutputNodeType = Node.CDATA_SECTION_NODE;
    }

    protected void writeDocType(DocumentType docType) throws IOException
    {
        if (docType != null)
        {
            docType.write(writer);
            writePrintln();
        }
    }

    protected void writeNamespace(Namespace namespace) throws IOException
    {
        if (namespace != null)
        {
            writeNamespace(namespace.getPrefix(), namespace.getURI());
        }
    }

    /**
     * Writes the SAX namepsaces
     * 
     * @throws IOException
     *             DOCUMENT ME!
     */
    protected void writeNamespaces() throws IOException
    {
        if (namespacesMap != null)
        {
            for (Iterator iter = namespacesMap.entrySet().iterator(); iter.hasNext();)
            {
                Map.Entry entry = (Map.Entry) iter.next();
                String prefix = (String) entry.getKey();
                String uri = (String) entry.getValue();
                writeNamespace(prefix, uri);
            }

            namespacesMap = null;
        }
    }

    /**
     * Writes the SAX namepsaces
     * 
     * @param prefix
     *            the prefix
     * @param uri
     *            the namespace uri
     * @throws IOException
     */
    protected void writeNamespace(String prefix, String uri) throws IOException
    {
        if ((prefix != null) && (prefix.length() > 0))
        {
            writer.write(" xmlns:");
            writer.write(prefix);
            writer.write("=\"");
        }
        else
        {
            writer.write(" xmlns=\"");
        }

        writer.write(uri);
        writer.write("\"");
    }

    protected void writeProcessingInstruction(ProcessingInstruction pi) throws IOException
    {
        // indent();
        writer.write("<?");
        writer.write(pi.getName());
        writer.write(" ");
        writer.write(pi.getText());
        writer.write("?>");
        writePrintln();

        lastOutputNodeType = Node.PROCESSING_INSTRUCTION_NODE;
    }

    protected void writeString(String text) throws IOException
    {
        if ((text != null) && (text.length() > 0))
        {
            if (escapeText)
            {
                text = escapeElementEntities(text);
            }

            // if (format.isPadText()) {
            // if (lastOutputNodeType == Node.ELEMENT_NODE) {
            // writer.write(PAD_TEXT);
            // }
            // }
            if (format.isTrimText())
            {
                boolean first = true;
                StringTokenizer tokenizer = new StringTokenizer(text);

                while (tokenizer.hasMoreTokens())
                {
                    String token = tokenizer.nextToken();

                    if (first)
                    {
                        first = false;

                        if (lastOutputNodeType == Node.TEXT_NODE)
                        {
                            writer.write(" ");
                        }
                    }
                    else
                    {
                        writer.write(" ");
                    }

                    writer.write(token);
                    lastOutputNodeType = Node.TEXT_NODE;
                    lastChar = token.charAt(token.length() - 1);
                }
            }
            else
            {
                lastOutputNodeType = Node.TEXT_NODE;
                writer.write(text);
                lastChar = text.charAt(text.length() - 1);
            }
        }
    }

    /**
     * This method is used to write out Nodes that contain text and still allow for xml:space to be
     * handled properly.
     * 
     * @param node
     *            DOCUMENT ME!
     * @throws IOException
     *             DOCUMENT ME!
     */
    protected void writeNodeText(Node node) throws IOException
    {
        String text = node.getText();

        if ((text != null) && (text.length() > 0))
        {
            if (escapeText)
            {
                text = escapeElementEntities(text);
            }

            lastOutputNodeType = Node.TEXT_NODE;
            writer.write(text);
            lastChar = text.charAt(text.length() - 1);
        }
    }

    protected void writeNode(Node node) throws IOException
    {
        int nodeType = node.getNodeType();

        switch (nodeType)
        {
        case Node.ELEMENT_NODE:
            writeElement((Element) node);

        break;

        case Node.ATTRIBUTE_NODE:
            writeAttribute((Attribute) node);

        break;

        case Node.TEXT_NODE:
            writeNodeText(node);

        // write((Text) node);
        break;

        case Node.CDATA_SECTION_NODE:
            writeCDATA(node.getText());

        break;

        case Node.ENTITY_REFERENCE_NODE:
            writeEntity((Entity) node);

        break;

        case Node.PROCESSING_INSTRUCTION_NODE:
            writeProcessingInstruction((ProcessingInstruction) node);

        break;

        case Node.COMMENT_NODE:
            writeComment(node.getText());

        break;

        case Node.DOCUMENT_NODE:
            write((Document) node);

        break;

        case Node.DOCUMENT_TYPE_NODE:
            writeDocType((DocumentType) node);

        break;

        case Node.NAMESPACE_NODE:

        // Will be output with attributes
        // write((Namespace) node);
        break;

        default:
            throw new IOException("Invalid node type: " + node);
        }
    }

    protected void installLexicalHandler()
    {
        XMLReader parent = getParent();

        if (parent == null)
        {
            throw new NullPointerException("No parent for filter");
        }

        // try to register for lexical events
        for (int i = 0; i < LEXICAL_HANDLER_NAMES.length; i++)
        {
            try
            {
                parent.setProperty(LEXICAL_HANDLER_NAMES[i], this);

                break;
            }
            catch (SAXNotRecognizedException ex)
            {
                // ignore
            }
            catch (SAXNotSupportedException ex)
            {
                // ignore
            }
        }
    }

    protected void writeDocType(String name, String publicID, String systemID) throws IOException
    {
        boolean hasPublic = false;

        writer.write("<!DOCTYPE ");
        writer.write(name);

        if ((publicID != null) && (!publicID.equals("")))
        {
            writer.write(" PUBLIC \"");
            writer.write(publicID);
            writer.write("\"");
            hasPublic = true;
        }

        if ((systemID != null) && (!systemID.equals("")))
        {
            if (!hasPublic)
            {
                writer.write(" SYSTEM");
            }

            writer.write(" \"");
            writer.write(systemID);
            writer.write("\"");
        }

        writer.write(">");
        writePrintln();
    }

    protected void writeEntity(Entity entity) throws IOException
    {
        if (!resolveEntityRefs())
        {
            writeEntityRef(entity.getName());
        }
        else
        {
            writer.write(entity.getText());
        }
    }

    protected void writeEntityRef(String name) throws IOException
    {
        writer.write("&");
        writer.write(name);
        writer.write(";");

        lastOutputNodeType = Node.ENTITY_REFERENCE_NODE;
    }

    protected void writeComment(String text) throws IOException
    {
        if (format.isNewlines())
        {
            println();
            indent();
        }

        writer.write("<!--");
        writer.write(text);
        writer.write("-->");

        lastOutputNodeType = Node.COMMENT_NODE;
    }

    /**
     * Writes the attributes of the given element
     * 
     * @param element
     *            DOCUMENT ME!
     * @throws IOException
     *             DOCUMENT ME!
     */
    protected void writeAttributes(Element element) throws IOException
    {
        // I do not yet handle the case where the same prefix maps to
        // two different URIs. For attributes on the same element
        // this is illegal; but as yet we don't throw an exception
        // if someone tries to do this
        for (int i = 0, size = element.attributeCount(); i < size; i++)
        {
            Attribute attribute = element.attribute(i);
            Namespace ns = attribute.getNamespace();

            if ((ns != null) && (ns != Namespace.NO_NAMESPACE) && (ns != Namespace.XML_NAMESPACE))
            {
                String prefix = ns.getPrefix();
                String uri = namespaceStack.getURI(prefix);

                if (!ns.getURI().equals(uri))
                {
                    writeNamespace(ns);
                    namespaceStack.push(ns);
                }
            }

            // If the attribute is a namespace declaration, check if we have
            // already written that declaration elsewhere (if that's the case,
            // it must be in the namespace stack
            String attName = attribute.getName();

            if (attName.startsWith("xmlns:"))
            {
                String prefix = attName.substring(6);

                if (namespaceStack.getNamespaceForPrefix(prefix) == null)
                {
                    String uri = attribute.getValue();
                    namespaceStack.push(prefix, uri);
                    writeNamespace(prefix, uri);
                }
            }
            else if (attName.equals("xmlns"))
            {
                if (namespaceStack.getDefaultNamespace() == null)
                {
                    String uri = attribute.getValue();
                    namespaceStack.push(null, uri);
                    writeNamespace(null, uri);
                }
            }
            else
            {
                char quote = format.getAttributeQuoteCharacter();
                writer.write(" ");
                writer.write(attribute.getQualifiedName());
                writer.write("=");
                writer.write(quote);
                writeEscapeAttributeEntities(attribute.getValue());
                writer.write(quote);
            }
        }
    }

    protected void writeAttribute(Attribute attribute) throws IOException
    {
        writer.write(" ");
        writer.write(attribute.getQualifiedName());
        writer.write("=");

        char quote = format.getAttributeQuoteCharacter();
        writer.write(quote);

        writeEscapeAttributeEntities(attribute.getValue());

        writer.write(quote);
        lastOutputNodeType = Node.ATTRIBUTE_NODE;
    }

    protected void writeAttributes(Attributes attributes) throws IOException
    {
        for (int i = 0, size = attributes.getLength(); i < size; i++)
        {
            writeAttribute(attributes, i);
        }
    }

    protected void writeAttribute(Attributes attributes, int index) throws IOException
    {
        char quote = format.getAttributeQuoteCharacter();
        writer.write(" ");
        writer.write(attributes.getQName(index));
        writer.write("=");
        writer.write(quote);
        writeEscapeAttributeEntities(attributes.getValue(index));
        writer.write(quote);
    }

    protected void indent() throws IOException
    {
        String indent = format.getIndent();

        if ((indent != null) && (indent.length() > 0))
        {
            for (int i = 0; i < indentLevel; i++)
            {
                writer.write(indent);
            }
        }
    }

    /**
     * <p>
     * This will print a new line only if the newlines flag was set to true
     * </p>
     * 
     * @throws IOException
     *             DOCUMENT ME!
     */
    protected void writePrintln() throws IOException
    {
        if (format.isNewlines())
        {
            String seperator = format.getLineSeparator();
            if (lastChar != seperator.charAt(seperator.length() - 1))
            {
                writer.write(format.getLineSeparator());
            }
        }
    }

    /**
     * Get an OutputStreamWriter, use preferred encoding.
     * 
     * @param outStream
     *            DOCUMENT ME!
     * @param encoding
     *            DOCUMENT ME!
     * @return DOCUMENT ME!
     * @throws UnsupportedEncodingException
     *             DOCUMENT ME!
     */
    protected Writer createWriter(OutputStream outStream, String encoding)
            throws UnsupportedEncodingException
    {
        return new BufferedWriter(new OutputStreamWriter(outStream, encoding));
    }

    /**
     * <p>
     * This will write the declaration to the given Writer. Assumes XML version 1.0 since we don't
     * directly know.
     * </p>
     * 
     * @throws IOException
     *             DOCUMENT ME!
     */
    protected void writeDeclaration() throws IOException
    {
        String encoding = format.getEncoding();

        // Only print of declaration is not suppressed
        if (!format.isSuppressDeclaration())
        {
            // Assume 1.0 version
            if (encoding.equals("UTF8"))
            {
                writer.write("<?xml version=\"1.0\"");

                if (!format.isOmitEncoding())
                {
                    writer.write(" encoding=\"UTF-8\"");
                }

                writer.write("?>");
            }
            else
            {
                writer.write("<?xml version=\"1.0\"");

                if (!format.isOmitEncoding())
                {
                    writer.write(" encoding=\"" + encoding + "\"");
                }

                writer.write("?>");
            }

            if (format.isNewLineAfterDeclaration())
            {
                println();
            }
        }
    }

    protected void writeClose(String qualifiedName) throws IOException
    {
        writer.write("</");
        writer.write(qualifiedName);
        writer.write(">");
    }

    protected void writeEmptyElementClose(String qualifiedName) throws IOException
    {
        // Simply close up
        if (!format.isExpandEmptyElements())
        {
            writer.write("/>");
        }
        else
        {
            writer.write("></");
            writer.write(qualifiedName);
            writer.write(">");
        }
    }

    protected boolean isExpandEmptyElements()
    {
        return format.isExpandEmptyElements();
    }

    /**
     * This will take the pre-defined entities in XML 1.0 and convert their character representation
     * to the appropriate entity reference, suitable for XML attributes.
     * 
     * @param text
     *            DOCUMENT ME!
     * @return DOCUMENT ME!
     */
    protected String escapeElementEntities(String text)
    {
        char[] block = null;
        int i;
        int last = 0;
        int size = text.length();

        for (i = 0; i < size; i++)
        {
            String entity = null;
            char c = text.charAt(i);

            switch (c)
            {
            case '<':
                entity = "&lt;";

            break;

            case '>':
                entity = "&gt;";

            break;

            case '&':
                entity = "&amp;";

            break;

            case '\t':
            case '\n':
            case '\r':

                // don't encode standard whitespace characters
                if (preserve)
                {
                    entity = String.valueOf(c);
                }

            break;

            default:

                if ((c < 32) || shouldEncodeChar(c))
                {
                    entity = "&#" + (int) c + ";";
                }

            break;
            }

            if (entity != null)
            {
                if (block == null)
                {
                    block = text.toCharArray();
                }

                buffer.append(block, last, i - last);
                buffer.append(entity);
                last = i + 1;
            }
        }

        if (last == 0)
        {
            return text;
        }

        if (last < size)
        {
            if (block == null)
            {
                block = text.toCharArray();
            }

            buffer.append(block, last, i - last);
        }

        String answer = buffer.toString();
        buffer.setLength(0);

        return answer;
    }

    protected void writeEscapeAttributeEntities(String txt) throws IOException
    {
        if (txt != null)
        {
            String escapedText = escapeAttributeEntities(txt);
            writer.write(escapedText);
        }
    }

    /**
     * This will take the pre-defined entities in XML 1.0 and convert their character representation
     * to the appropriate entity reference, suitable for XML attributes.
     * 
     * @param text
     *            DOCUMENT ME!
     * @return DOCUMENT ME!
     */
    protected String escapeAttributeEntities(String text)
    {
        char quote = format.getAttributeQuoteCharacter();

        char[] block = null;
        int i;
        int last = 0;
        int size = text.length();

        for (i = 0; i < size; i++)
        {
            String entity = null;
            char c = text.charAt(i);

            switch (c)
            {
            case '<':
                entity = "&lt;";

            break;

            case '>':
                entity = "&gt;";

            break;

            case '\'':

                if (quote == '\'')
                {
                    entity = "&apos;";
                }

            break;

            case '\"':

                if (quote == '\"')
                {
                    entity = "&quot;";
                }

            break;

            case '&':
                entity = "&amp;";

            break;

            case '\t':
            case '\n':
            case '\r':

            // don't encode standard whitespace characters
            break;

            default:

                if ((c < 32) || shouldEncodeChar(c))
                {
                    entity = "&#" + (int) c + ";";
                }

            break;
            }

            if (entity != null)
            {
                if (block == null)
                {
                    block = text.toCharArray();
                }

                buffer.append(block, last, i - last);
                buffer.append(entity);
                last = i + 1;
            }
        }

        if (last == 0)
        {
            return text;
        }

        if (last < size)
        {
            if (block == null)
            {
                block = text.toCharArray();
            }

            buffer.append(block, last, i - last);
        }

        String answer = buffer.toString();
        buffer.setLength(0);

        return answer;
    }

    /**
     * Should the given character be escaped. This depends on the encoding of the document.
     * 
     * @param c
     *            DOCUMENT ME!
     * @return boolean
     */
    protected boolean shouldEncodeChar(char c)
    {
        int max = getMaximumAllowedCharacter();

        return (max > 0) && (c > max);
    }

    /**
     * Returns the maximum allowed character code that should be allowed unescaped which defaults to
     * 127 in US-ASCII (7 bit) or 255 in ISO- (8 bit).
     * 
     * @return DOCUMENT ME!
     */
    protected int defaultMaximumAllowedCharacter()
    {
        String encoding = format.getEncoding();

        if (encoding != null)
        {
            if (encoding.equals("US-ASCII"))
            {
                return 127;
            }
        }

        // no encoding for things like ISO-*, UTF-8 or UTF-16
        return -1;
    }

    protected boolean isNamespaceDeclaration(Namespace ns)
    {
        if ((ns != null) && (ns != Namespace.XML_NAMESPACE))
        {
            String uri = ns.getURI();

            if (uri != null)
            {
                if (!namespaceStack.contains(ns))
                {
                    return true;
                }
            }
        }

        return false;
    }

    protected void handleException(IOException e) throws SAXException
    {
        throw new SAXException(e);
    }

    // Laramie Crocker 4/8/2002 10:38AM

    /**
     * Lets subclasses get at the current format object, so they can call setTrimText, setNewLines,
     * etc. Put in to support the HTMLWriter, in the way that it pushes the current newline/trim
     * state onto a stack and overrides the state within preformatted tags.
     * 
     * @return DOCUMENT ME!
     */
    protected OutputFormat getOutputFormat()
    {
        return format;
    }

    public boolean resolveEntityRefs()
    {
        return resolveEntityRefs;
    }

    public void setResolveEntityRefs(boolean resolve)
    {
        this.resolveEntityRefs = resolve;
    }
}

/*
 * Redistribution and use of this software and associated documentation ("Software"), with or
 * without modification, are permitted provided that the following conditions are met: 1.
 * Redistributions of source code must retain copyright statements and notices. Redistributions must
 * also contain a copy of this document. 2. Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution. 3. The name "DOM4J" must not be used to
 * endorse or promote products derived from this Software without prior written permission of
 * MetaStuff, Ltd. For written permission, please contact dom4j-info@metastuff.com. 4. Products
 * derived from this Software may not be called "DOM4J" nor may "DOM4J" appear in their names
 * without prior written permission of MetaStuff, Ltd. DOM4J is a registered trademark of MetaStuff,
 * Ltd. 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org THIS SOFTWARE IS
 * PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Copyright 2001-2005
 * (C) MetaStuff, Ltd. All Rights Reserved.
 */
